Bronchoalveolar lavage in the normal lung: First of three parts: Protein, enzymatic and ionic features

Bronchoalveolar lavage was performed on 12 healthy volunteers, comprising 6 smokers and 6 nonsmokers, of ages between 21 and 52 years. The aim was to define normal variability of certain biochemical, immunologic, enzymologic and ionic parameters. The smoking habit was observed to exert a significant influence on the recovery percentage of lavage effluents (with recovery less in smokers, 53 vs. 69%) and particularly on the concentration of immunoglobulins in the lavage liquids. In particular, the IgG increased by about 4 times in smokers (1.05 vs. 0.26 mg/100 ml) and the IgA by about 3 times (0.35 vs. 0.11 mg/100 ml). The other parameters studied (total proteins, albumins, IgM, α₁AT, K, Ca and several enzyme activities) did not differ significantly from one group to the other. Rather than an alteration in the blood-alveolar barrier from smoking, these data suggest a real local overproduction of immunoglobulins of classes G and A induced by the smoking habit. Moreover, the relatively slight individual oscillation in the values of the parameters studied in the two groups supports the possibility of employing them for diagnostic purposes in bronchopneumopathies.